Fig. 3
From: The genomic and functional landscapes of developmental plasticity in the American cockroach
Gene repertoire of the innate immune system and functional analyses of the Toll pathway in P. americana. a Representation of three main innate immune signaling pathways (Imd, Toll, and JAK-STAT, proposed in Drosophila)22,23,24 in P. americana. Genes from expanded gene families in P. americana are highlighted in red. Since all genes absent in P. americana were also found to be absent in other insect species, they were defined as Drosophila-specific components and outlined by gray dashed lines. 1, fas-associated DD protein; 2, death-related Ced-3/Nedd2-like protein; 3, effete; 4, TAK1-binding protein 2; 5, TGF-β-activated kinase 1; 6, kenny; 7, immune response deficient 5; 8, spätzle-processing enzyme; 9, myeloid differentiation primary response 88; 10, tube; 11, hopscotch; 12, socs36E; AMP, antimicrobial peptide; DOME, domeless; Dnr1, defense repressor 1; GNBP, Gram-negative binding protein; Gprk2, G protein-coupled receptor kinase 2; Grass, Gram-positive-specific serine protease; Iap2, inhibitor of apoptosis 2; IMD, immune deficiency; ModSP, modular serine protease; PGN, peptidoglycan; PGRP, peptidoglycan recognition protein; Pirk, poor IMD response upon knock in; Spz, spätzle; Spirit, serine protease immune response integrator; Stat92E, signal transducer and activator of transcription protein at 92E. Detailed information is additionally shown in Supplementary Tables 11–15. b Functional verification of genes in the Toll pathway against a classic Gram-positive bacterium, Staphylococcus aureus. Four major genes in the Toll pathway were knocked down by RNAi, compared to injection of control dsRNA (CK, a 92 bp non-coding sequence from the pSTBlue-1 vector). Corresponding mortality is shown upon S. aureus infection. Injection of cockroach saline solution (CSS, as a control) or S. aureus was performed 24 h after dsRNA injection. Error bars indicate standard deviation of three replicates. Bars labeled with different lowercase letters indicate significant difference between the two samples, with p < 0.05, one-way analysis of variance (ANOVA). c Functional relationship between the Toll pathway and expression of AMPs. Dorsal, a key component in the Toll pathway whose depletion caused the greatest mortality (shown in b), was knocked down by RNAi. Correspondingly, the relative expression of 11 antimicrobial peptide genes were measured and shown in c. Error bars represent s.d. of three replicates. Two-tailed Student's t-test: *p < 0.05; **p < 0.01
